The present invention is broadly concerned with a concrete vibrator apparatus. More particularly, it is concerned with a portable, hand held vibrator for use in conjunction with insulated concrete forms.
Modern building techniques for construction of concrete walls in commercial and residential structures frequently employ insulated concrete forms (ICF). These forms are constructed of a plastic foam material such as expanded polystyrene, extruded polystyrene, polyurethane or cement-foam composites. The foams are inert, nonabsorbent, are superior insulators, having extremely high R-values per inch, and are good barriers against air and moisture. The foams are also lightweight and easy to form or cut into blocks and panels.
Foam block units are generally of interlocking construction, which may be stacked into spaced-apart, open top walls which may be joined together using appropriate ties to produce hollow forms. Panel and plank units are stacked atop each other in parallel relation to form spaced-apart, open-top walls which may also be joined together using appropriate ties to produce similar hollow forms. Once constructed, the forms may be braced with wood and/or metal bracing members, and reinforcing rods placed therein. Concrete slurry is poured or pumped into the central cavity and permitted to cure, generally for about 48 hours. When the bracing is removed, the forms remain in place and are covered by interior and exterior finishing materials such as drywall, plaster, stucco, siding, brick or stone. This method of construction is increasingly popular because the finished structure is strong, durable, quiet, air tight and well insulated. Such structures are unusually energy efficient because the composite walls produce superior insulation qualities with reduced air infiltration.
Clearly, the integrity of a structure consisting of a layer of concrete sandwiched between layers of an insulating foam skin is dependent on the homogeneity of the concrete core. Air pockets and bubbles can negatively affect all of the beneficial qualities of the concrete and, if they are sufficiently large in size, can compromise its structural integrity as well.
Traditional concrete construction employs metal and/or wooden forms and such voids are commonly eliminated from wet concrete using a vibrator before the mix cures. In order to accomplish this, a worker often stands atop the form; inserts an elongated vibrator into the wet concrete between the rebar reinforcement rods and moves the vibrator up and down in the concrete between the forms to urge bubbles to the open surface. Such methods are generally not applicable to ICF construction because of the relative fragility of the plastic foam. Because the conventional vibrator must be elongated for reaching to the bottom of the wall structure, it is not easily controlled and may bump against the walls of the form. While wooden or metal form walls can withstand such rough handling, the more fragile foam forms may be punctured or displaced by vibrator contact. Foam forms are also subject to “blow outs” if subject to excessive bumping or rough handling, which might occur if a worker attempted to insert a vibrator shaft into the form from an adjacent scaffolding or ladder.
Wall contacting vibrators are known in the prior art. However, they are generally too heavy or cumbersome for hand held use, require physical attachment at locations along the form and/or are likely to damage foam forms.
Thus, there is a need for a concrete vibratory device having structure for contacting a foam wall and transmitting vibratory contact force; that can be moved along the exterior surface to remotely compact the concrete inside the form without form damage, and that is portable, light weight and hand held so that it can easily be controlled by a user.